Theater-dimmer.



No. 628,685. Patontod luly ll, I899.

A. W. BERRESFORD. v

THEATER DIIIER.

(Applicltion am I. 27, 1899.)

(No Model.)

, i B I 1 e fifinan evvqa d UNITED STATES PATENT OFFICE.

ARTHUR \V. I'BERRESFORD, OF INESTFIELD, NE\V JERSEY.

THEATER-DIMMER.

SPECIFICATION forming part of Letters Patent No. 628,685, dated July 11, 1899. Application filed February 27,1899. Serialll'o. 706,967. No model.)

To all, whom 716 may 0072106771,.

Be it known that I, ARTHUR \V. Bunnies FORiD,a citizen of the United States, and a resident of \Vestlield, in the county of Union and State of New Jersey, have invented a new and useful Improvement in Theater-Dimmers, of which the following is a specification.

In obtaining the lighting effects used in connection with theatrical productions to produce the illusions called for by the piece it is necessary to mix the various colors of light and to obtain gradual changes for vary ing the quantity of light of each color by variation in the amount emitted by each source of light. This is accomplished by introducing a gradually increasing or decreasing resistance into the lamp-circuit, and thus controlling the current supplied.

In the construction of apparatus for producin g the above effects, which apparatus are generally known as "theater-dimmers, i t has been the practice to assemble or bank the re sistance-plates into a rigid whole by passing tie-rods through the plates and into supporting-frames therefor and separating the several plates by short lengths of pipe surrounding the rods between the plates. In this structure it was necessary to remove more or less of the apparatus to remove any one of the resistance-plates if for any cause the removal of such plate became desirable. In operation it becomes necessary to move several of the independent contact-levers at the same time to produce a certain effect. This is ordinarily accomplished by providing a master-lever shaft which is mounted in brackets carried by the resistance-plates, which shaft communicates motion to the several contactlevers by rigid connections with segments mounted to rotate freely on the axes of the contact-levers, which segments are arranged to interlock with the said contact-levers.

One object of my invention is to obviate the necessity of knocking down the structure to remove any one of the resistance-plates, the said plates in my improved structure being independently mounted in the supportingframework.

Another object of my invention is to mount the master-lever shaft in the frame independ ently of the resistance-plates in such a man nor as to permit the said shaft to be adjusted laterally and vertically without interfering with the said plates, to compensate for any distortion in the framework due to derangement in shipment, unevenness of setting, &c. This structure enables any one of the plates to be removed without removing the shaft and without disturbing any of the remaining plates, and, further, obviates the difficulties which occur in attempting to aline the holes in the several plates so as to mount the shaft therein as has heretofore been customary.

A further object is to provide flexible connections between the master-lever shaft and the several contact-lever segments or wheels, so as to insure the easy operation of the said levers by the master-lever without any tendency to bind or cramp.

Astill further object is to provide means for reversing the flexible connection between the master-lever shaft and any of the several contact-levers, so that when the master-lever is swung in one direction certain of the contactlevers will be caused to swing in the reverse direction when interlocked with their segments or wheels to produce certain desired effects.

A practical embodiment of my invention is represented in the accompanying drawings, in which Figure 1 represents my improved apparatus in end elevation. Fig. 2 is a side view of the same. Fig. 3 is a transverse vertical section in the plane of the line 3 3 of Fig. 2. Fig. 4: is an enlarged detail sectional view of one form of insulating adjustable coupling for securing together the free ends of the flexible connections, and Fig. 5 represents a detail View showing the manner of crossing the flexible connections to reverse the movement of the contact-lever segment or wheel.

The resistance-plates are denoted by A, and

the supporting-frame therefor comprises upright frames 1-3 and cross-bars B 13 B which cross-bars serve to connect the upright frames. Two of these upright frames B, are shown in the accompanying drawings as end frames; but it is to be understood that there may be one or more intermediate upright frames to strengthen the structure where a large number of resistance-plates are carried by the frame, if found desirable.

The several cross-bars B B may be u provided with a plurality of wheels or segthe segment or wheel D.

bolted firmly to the upright frames l3, so as 7 to produce a rigid structure. In the accompanying drawings l have represented the upper cross-bar 13 as a flat bar, the rear lower cross-bar B as a T-bar,and the front cross-bar 13 as an L-bar.

I have represented a bank of four resistanceplates A in the accompanyingdrawings, but there may be a greater or lesser number, acl cording to different requirements. Each of these plates A is removably secured to the several cross-bars independentlyof the other plates in the following manner: The plate A rests upon the lower cross-bars B B and is secured to the front lower cross-bar B by bolts 1), which pass through the said cross-bar and through lugs a, extended laterally from the front of the lower edge of said plate. The I plate is secured to the rear lower cross-bar B by means of bolts Z), which pass through the said cross-bar and through lugs (4, extended laterally from the bottom of the rear edge of 5 the said plate. Theplate is also bolted to the upper crossbar B by means of bolts b which pass through the said cross-bar and through lugs 0 projecting laterallyfrom the top ofthe rear edge of the said plate.

The contact-lever is denoted by C, and it is mounted on a stub-axle a projecting from about the middle of the plate A. The contactlever-controlling segment or wheel is denoted byD,anditis mounted to rock freely upon the stub-axle a and is fitted to be interlocked with the said contact-lever. The means which I have shown for interlocking the lever and segment or wheel consists of a dog 0, arranged to enter a notch d in the periphery of This dog 0 is connected to an operating-handle 0, located at the handle of the contact-lever. The dog may be held in its raised position for releasing the lever from the segment or wheel D by means ofa ring 0 which embraces the handle 0 and the handle of the contactlever. The contactlever C may be provided with the usual contact-plates c 0, arranged to travel over the upper and lower series of contact-points (0 0.

In order to move several of the independent contact-levers C at the same time, 1 provide a master-lever shaft E, which shaft is ments 6, mounted fast thereon, corresponding to the contact-leversegments or wheels D.

The shaft E is provided with a master-lever 0, which extends upwardly in the present instance to a point above the frame between one of the end upright frames 13 and the adjacent resistanceplate. However, the master-lever might project from the said shaft at any place along the bank of resistance' plates as found desirable.

The segments or wheels 0 impart a rock ing movement to the wheels or segments D through flexible connections l Each of these flexible connections F preferably consists of a wire rope divided into two sections having their adjacenteiuls clamped within insulating-couplings G, so that there will be no electrical connection between the upper segment or wheel and the lower segment or wheel. This insulating-coupling G is arranged to take up any slack in the rope F, as

it is essential that the said flexible connection or rope shall be very taut, so as to insure the proper operation of the contact-lever controlled thereby. In the present instance the ends of the rope are held in position within the coupling by means of set-screws g g. \Vhen it is desired to move the contact-lever in the same direction as the movement of the I master-lever, the rope leads from one side of the periphery of the lower segment or wheel to the same side of the upper segment or wheel. When it is desired to cause the contact-lever to move in the opposite direction 3 periphery at the other side of the upper segment or wheel. This flexible connection is preferably wire rope or other suitable material which will not stretch.

The master-lever shaft E is mounted to rock in the upright frames B in such a manner that it may be adjusted both laterally and vertically to accon'nnodate itself to any unevenness in the setting of the frame. In the present instance this adjustment is secured by providing each end of the shaft with a bearing-sleeve a which sleeve is engaged on each side by adj listing-screws 6 carried by a vertically-adjustable bracket c, carried by one of the upright frames B. In the present instance these brackets are made vertically adjustable by providing them with verticallyelongated slots 0 through which bolts 0 pass into engagement with the said upright frame.

In the structure as above described the -master-lever shaft is mounted in the frame entirely independent of the several resistance-plates,so that anyof the said resistanceplates may be removed without disturbing the said shaft.

XV hat I claim is- 1. A theater-dimmer comprising asuitable supporting-frame, a plurality of resistance plates, a contact-lever and contact-points carried by each plate independently of adjacent plates and means for securing each plate to the supporting-frame in removable adj ustment, substantially as set forth.

2. A theater-dimmer comprising a support ing-frame consisting of upright frames and cross-bars connecting the said frames, a plurality of resistance-plates, a contact-lever and contact-points carried by each plate independently of adjacent plates and means for securing each plate to the said cross-bars in removable adjustment, substantially as set forth.

3. A theater-dimmer comprising a supporting-frame, resistance-plates carried thereby, contact-levers for the resistancc-plates and a ins-frame, aplurality of resistance-plates car master-lever shaft connected With the said. contact-levers, the said shaft being mounted in the supporting-frame independently of the said resistance-plates, substantially as set forth.

:1. A theaier-dinnn er com prising a support ried thereby, contact-levers for the plates, a master-lever shaft connected with the said contact-levers and mounted in the frame independently of the resistance plates, and means for adjusting the shaft laterally and vertically, for the purpose set forth.

5. A theater-dimmer com prising}; a supporting-frame, resistance-plates carried thereby, contact-levers,segments or wheels arranged to interlock with said levers, a master-lever shaft mounted in the frame, segments or wheels carried thereby and flexible connections between the contact lever segments or Wheels and the m aster-lever shaft segments or Wheels, substantially as set forth.

6. A theater-dimmer comprising a supporting-frame, resistance-plates carried thereby, contact-levers, contact -lever segments or wheels arranged to interlock with the contact levers, a master-lever shaft mounted in the frame, segments or Wheels carried by the said shaft, flexible connections between the contact-lever segments or Wheels and the masterlever-shaft segments or Wheels, and means for reversing the said flexible connections whereby one or more of the contact-lever segments or Wheels may be caused to rock in the reverse direction to the movement of the master-lever-shaft segments or wheels, substantially as set forth.

7. A theater-dimmer comprising a supporting-frame, resistance-plates carried thereby, contact-levers therefor, contact-lever segments or Wheels arranged to interlock With the said levers, a master-lever shaft mounted in the frame, segments or Wheels carried thereby, flexible connections between the shaft segments or wheels and the contact-leyer segments or Wheels comprising upper and lower sections and means for insulating, the upper and lower sections of the flexible con.- nections and adjusting their tension, substantially as set forth.

In testimony that I claim the foregoing as my invention I have signed my name, in presence of two Witnesses, this 23d day of February, 1899.

ARTHUR N. BERRESFORD.

Nitnesses:

FREDK. HAYNES, EDWARD VIEsER. 

